CN102467028B - Image forming apparatus - Google Patents

Image forming apparatus Download PDF

Info

Publication number
CN102467028B
CN102467028B CN201110344603.XA CN201110344603A CN102467028B CN 102467028 B CN102467028 B CN 102467028B CN 201110344603 A CN201110344603 A CN 201110344603A CN 102467028 B CN102467028 B CN 102467028B
Authority
CN
China
Prior art keywords
image
developer
bearing member
image forming
developing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN201110344603.XA
Other languages
Chinese (zh)
Other versions
CN102467028A (en
Inventor
铃木慎也
福田正史
堀卓也
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Publication of CN102467028A publication Critical patent/CN102467028A/en
Application granted granted Critical
Publication of CN102467028B publication Critical patent/CN102467028B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/02—Apparatus for electrographic processes using a charge pattern for laying down a uniform charge, e.g. for sensitising; Corona discharge devices
    • G03G15/0266—Arrangements for controlling the amount of charge
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/065—Arrangements for controlling the potential of the developing electrode
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/55—Self-diagnostics; Malfunction or lifetime display
    • G03G15/553—Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/06—Developing structures, details
    • G03G2215/0602—Developer
    • G03G2215/0604—Developer solid type
    • G03G2215/0607—Developer solid type two-component
    • G03G2215/0609—Developer solid type two-component magnetic brush

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Dry Development In Electrophotography (AREA)
  • Developing For Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Color Electrophotography (AREA)

Abstract

The present invention relates to an image forming apparatus. A control unit decreases the potential difference according to an increase in the drive amounts of the image bearing member and the developer bearing member, based on a first information about a drive amount of the image bearing member and second information about a drive amount of the developer bearing member, in a case that an integrated value of the first information and the second information from initial installation or replacement of the developing device is greater than a predetermined value.

Description

Image forming apparatus
Technical field
The present invention relates to the image forming apparatus using electrophotographic method or electrostatic recording method.Especially, the present invention relates to the such as duplicating machine of the holding member comprising the gap remained between image bearing member and developer bearing part, the image forming apparatus of printer or facsimile recorder and so on.
Background technology
Traditionally, the use such as duplicating machine of electrophotographic method, the image forming apparatus of printer or facsimile recorder and so on comprise the development sleeve be arranged in the position relative with photosensitive drums.Photosensitive drums is the image bearing member it being formed with electrostatic latent image, and development sleeve is the developer bearing part carrying and transmit developer.Then image forming apparatus general execution uses developer to make the visual development treatment of electrostatic latent image wherein.
The image forming apparatus of two-component developing method is used to use two-component developing agent, with predetermined ratio mixing nonmagnetic toner and magnetic carrier in this developer.When this image forming apparatus performs development treatment, photosensitive drums and development sleeve have predetermined gap (that is, S-D gap) when among each other and arrange relative to one another.Then developing bias is applied to development sleeve, makes to use the toner in developer to perform development treatment.In this case, if S-D gap is too wide, be then reduced in the electric field intensity between photosensitive drums and development sleeve, make to become more be difficult to perform development treatment.On the other hand, if S-D gap is too narrow, then electric field intensity becomes excessive, makes to become easily to produce abnormal electric discharge, and the image deflects of such as ring-type point and so on may occur.
In order to address this is that, Japanese Patent Application Publication No.07-175321 discusses the following image forming apparatus remained in S-D gap in preset range.Just adjacent drum surface is sentenced in the marginal portion that clearance maintaining member is disposed in development sleeve.
But, as in Japanese Patent Application Publication No.07-175321 discuss comprise and clearance maintaining member attached to development sleeve to go wrong in the image forming apparatus of the image formation unit of adjacent photosensitive drums.More particularly, due to the rotation of photosensitive drums or development sleeve and the friction existed clearance maintaining member.As a result, clearance maintaining member becomes and is worn, and makes S-D space change.Especially, set in the image forming apparatus of difference wherein between the photosensitive drums be arranged opposite to each other and development sleeve, wearing and tearing are significant.Difference is set to make to transmit a large amount of developer in developing cell (that is, photosensitive drums and development sleeve arrange relative to one another part), thus raising developing performance.If S-D gap narrows due to the wearing and tearing of clearance maintaining member, then development sleeve to carry and the two-component developing agent transmitted by development sleeve becomes and is difficult to by S-D gap.Therefore in the region of S-D air gap periphery, there is the delay of developer.
Developer comprises magnetic carrier, and the thin layer of this magnetic carrier is applied on development sleeve, and this magnetic carrier is carried by the magnet be arranged in development sleeve.If there is the delay of developer as described above in the region of S-D air gap periphery, then developer movement can not keep the position of the developer comprising magnetic carrier to the magnetic force of wherein magnet.Then, the developer comprising magnetic carrier overflows from developing apparatus, and finally becomes and discharge from image forming apparatus the transfer materials that it is attached with magnetic carrier.In addition, the magnetic carrier overflowed from developing apparatus is sent to transfer printing unit or fixation unit together with toner image, image forming apparatus body is become and is greatly damaged.
Summary of the invention
One of aspect of the present invention relates to the image forming apparatus of the inefficacy that can reduce caused by the delay of the developer occurred near part that development sleeve and photosensitive drums arrange relative to one another.This delay of developer is caused by being kept the wearing and tearing of the clearance maintaining member in the gap between developer bearing part and image bearing member by contiguous image load bearing component.
According to a further aspect in the invention, a kind of image forming apparatus comprises: image bearing member, developing apparatus, described developing apparatus is included in the developer bearing part relatively arranged with described image bearing member in developing regional, and be configured to the latent electrostatic image developing making to be formed on described image bearing member, described developer bearing part carries and transmits the developer comprising nonmagnetic toner and magnetic carrier, clearance maintaining member, described clearance maintaining member is integrally replaced together with described developing apparatus, and is configured to remain on distance between described image bearing member and described developer bearing part by adjacent described image bearing member and described developer bearing part, and control module, described control module is configured to control the potential difference (PD) between the current potential and the developing bias being applied to described developer bearing part of the non-image portion of described image bearing member, wherein based on the second information of the first information of the drive volume about described image bearing member and the drive volume about described developer bearing part, when the initial installation from described developing apparatus of the first information and the second information or the integrated value since replacing are greater than predetermined value, described control module reduces described potential difference (PD) according to the increase of the drive volume of described image bearing member and described developer bearing part.
According to the detailed description of the exemplary embodiment below with reference to accompanying drawing, the present invention's more characteristic sum aspect will become clear.
Accompanying drawing explanation
To be added into and the accompanying drawing forming an instructions part shows exemplary embodiment of the present invention, characteristic sum aspect, and to be used for together with the description explaining principle of the present invention.
Fig. 1 is the schematic diagram of the configuration of the example illustrated according to image forming apparatus of the present invention.
Fig. 2 illustrates that the image in the image forming apparatus shown in Fig. 1 forms the schematic diagram at station.
Fig. 3 illustrates that the first image in the image forming apparatus shown in Fig. 1 forms the schematic diagram of station Pa.
Fig. 4 is the schematic diagram of the clearance maintaining member 49 illustrated according to the first exemplary embodiment.
Fig. 5 is the schematic diagram in the region illustrated around according to the developing cell in the image forming apparatus of the first exemplary embodiment.
Fig. 6 A and Fig. 6 B illustrates according to the current potential in the developing cell in the image forming apparatus of the first exemplary embodiment.
Fig. 7 illustrates the curve map according to the demist current potential in the image forming apparatus of the first exemplary embodiment, relation between S-D gap and the delay of developer.
Fig. 8 is the block diagram that control module and the detecting unit controlled according to the execution of the first exemplary embodiment is shown.
Fig. 9 illustrates the process flow diagram for performing the process of high voltage control based on the driving of development sleeve according to the first exemplary embodiment.
Figure 10 illustrates for performing the Vback table controlled according to development count value.
Figure 11 illustrates the process flow diagram for performing the process of high voltage control based on the wear extent of clearance maintaining member according to the first exemplary embodiment.
Figure 12 illustrates the process flow diagram for controlling the process of contrast (contrast) current potential based on the wear extent of clearance maintaining member according to the first exemplary embodiment.
Figure 13 is the schematic diagram of another example illustrated according to image forming apparatus of the present invention.
Figure 14 is the schematic diagram of another example of the clearance maintaining member 49 illustrated according to the first exemplary embodiment.
Figure 15 is the schematic diagram of the clearance maintaining member 49 illustrated according to the second exemplary embodiment.
Figure 16 illustrates the process flow diagram for performing the process of high voltage control based on the wear extent of clearance maintaining member according to the 3rd exemplary embodiment.
Figure 17 illustrates the process flow diagram for replacing the process of handle box based on the wear extent instruction of clearance maintaining member according to the 4th exemplary embodiment.
Embodiment
Describe each exemplary embodiment of the present invention, feature and aspect below with reference to the accompanying drawings in detail.
To describe below according to the first exemplary embodiment of the present invention.Fig. 1 and Fig. 2 is the sectional view of the example of the color image forming illustrated according to use intermediate transfer method of the present invention.According to this exemplary embodiment, image forming apparatus is the electro photography laser beam printer using contact electrification method to contact the cleaner-less of developing method with bi-component.
With reference to Fig. 1, be included according to the image forming apparatus 100 of this exemplary embodiment four images that image working direction is arranged continuously and form station Pa, Pb, Pc and Pd.It is the handle box removably attaching to image forming apparatus 100 that four images form station Pa, Pb, Pc and Pd.
Fig. 2 illustrates that image forms the sectional view of station Pa.Four images form station Pa, Pb, Pc and Pd and are formed similarly.With reference to Fig. 2, image forms station Pa and comprises photosensitive drums 1a (i.e. image bearing member), Charging system 2a, exposure device 3a, developing apparatus 4a, upstream subband electric installation 51a and downstream subband electric installation 52a.In addition, intermediate transfer belt 11 (i.e. intermediate transfer element) is arranged such that to move up in the side pointed out by the arrow shown in Fig. 2.Therefore, intermediate transfer belt 11 is by primary transfer device 7a, 7b, 7c and 7d in each in image formation station Pa, Pb, Pc and Pd and photosensitive drums 1a, 1b, 1c and 1d.
Get back to Fig. 1, the scanner unit 31 comprising light source 32, polygonal mirror 33 and exposure window 34 is disposed in the bottom of image forming apparatus 100.Polygonal mirror 33 rotates and scans the laser beam of launching from light source 32, and multiple reflective mirror makes the light beam deflection of scan light.F θ lens make the light of deflection assemble and utilize the light assembled that the bus of each photosensitive drums in photosensitive drums 1a, 1b, 1c and 1d is exposed.Therefore in photosensitive drums, form the electrostatic latent image according to picture signal.
Four image developing apparatus 4a, 4b, 4c and 4d formed in station Pa, Pb, Pc and Pd are respectively filled with the two-component developing agent of scheduled volume.More particularly, in often kind of two-component developing agent, yellow, magenta, cyan or black non-magnetic toner mix with magnetic carrier with predetermined mixing ratio respectively.Therefore, the sub-image that developing apparatus 4a, 4b, 4c and 4d use the toner of often kind of color sequentially to develop in photosensitive drums, and form toner image.Then toner image is transferred to intermediate transfer belt 11.In addition, the transfer materials P be included in transfer materials box 14 is sent to secondary transfer printing device 12, and the toner image that intermediate transfer belt 11 carries is transferred secondarily to transfer materials P.Fixation unit 9 performs heating and pressurization, to make the toner image on transfer materials P, and then has the transfer materials P of toner image to be discharged to outside image forming apparatus 100 as record image using fixing on it.
Clean secondary transfer printing residual toner or the demist toner being attached to the surface of intermediate transfer belt 11 of intermediate transfer belt cleaning doctor (blade) 13.Intermediate transfer belt cleaning doctor 13 is at the downstream part adjacent intermediate transfer belt 11 always of the moving direction relative to intermediate transfer belt 11 of secondary transfer printing part.On the other hand, upstream subband electric installation 51a, downstream subband electric installation 52a and Charging system 2a perform carried charge control after, in developing apparatus 4a collect stay image formed station Pa in photosensitive drums 1a on primary transfer residual toner.Also formed in station at other image and perform similar process.
In addition, image forming apparatus 100 comprises the CPU (central processing unit) (CPU) 61 controlling image forming apparatus.CPU 61 is connected with the random access storage device (RAM) 62 and ROM (read-only memory) (ROM) 63 being used as working storage, and this ROM (read-only memory) (ROM) 63 stores the program and various data that will be performed by CPU 61.
Charge process will be described below.Below with reference to Fig. 2 and Fig. 3 description according to the image forming course performed in the photosensitive drums of this exemplary embodiment and peripheral components.Fig. 3 illustrates that the first image in image forming apparatus forms the schematic diagram of station Pa.According to this exemplary embodiment, image forming apparatus forms image with the processing speed of 130mm/sec.
Image forming apparatus 100 applies high pressure on contact electrification device 2a, to make, photosensitive drums 1a's is uniformly charged.According to this exemplary embodiment, contact electrification device 2a is charged roller.But contact electrification parts can also have other shape and material, such as hairbrush and felt (felt).In addition, can in conjunction with various material to form the contact electrification parts with more suitably elasticity, electric conductivity, surface nature and permanance.
Each end of the core (core) of charged roller 2a is kept to make freely to be rotated by load bearing component (not shown).In addition, pressing spring 21a makes charged roller 2a be partial to photosensitive drums 1a, and charged roller 2a is contacted with the surface-pressure of predetermined plus-pressure and photosensitive drums 1a.As a result, charged roller 2a is rotatably driven together along with the rotation of photosensitive drums 1a.High-voltage power supply 101a applies the band electrical bias voltage of predetermined condition on the core of charged roller 2a.Therefore, the surface of the photosensitive drums 1a of rotation is touched charged to predetermined polarity and current potential.
According to this exemplary embodiment, the band electrical bias voltage being applied to charged roller 2a is wherein direct current (DC) voltage and the oscillating voltage exchanging (AC) voltage superposition.More particularly, electrical bias voltage is with to be the DC voltage of-700V and the oscillating voltage of AC voltage superposition of sine wave with 1.3kHz frequency and peak-to-peak voltage Vpp=1.5kV.Therefore, band electrical bias voltage makes the uniformly charged of photosensitive drums 1a arrive-700V (that is, dark potential Vd), and it is substantially identical with the DC voltage being applied to charged roller 2a.
Then image forming apparatus 100 uses exposure device 3a to form electrostatic latent image on charged photosensitive drums 1a.According to this exemplary embodiment, exposure device 3a is the laser beam scanner using semiconductor laser.
Developing process will be described below.Developing apparatus 4a in image forming apparatus 100 carrys out supplying toner according to the electrostatic latent image formed on photosensitive drums 1a, makes to form toner image (that is, developer image).According to this exemplary embodiment, developing apparatus uses bi-component contact developing method.In this approach, by making to contact come developing electrostatic latent image with the Magnetic brush that the two-component developing agent of magnetic carrier is formed with photosensitive drums by comprising nonmagnetic toner.
Developing apparatus 4a comprises nonmagnetic development sleeve 41a (that is, developer bearing part), and in this development sleeve, magnet 42a is fixedly placed in its inside.A part for the external peripheral surface of development sleeve 41a is exposed to developing apparatus 4a outside.Development sleeve 41a is disposed near photosensitive drums 1a and in the position relative with photosensitive drums 1a, keeps the distance (that is, S-D gap) nearest with photosensitive drums 1a to be 300 μm.
Photosensitive drums 1a and development sleeve 41a is developing regional by the region of placing relative to one another wherein.The clearance maintaining member 49 in S-D gap is kept to be attached to axially two ends of development sleeve 41a, so that adjacent photosensitive drums 41a.In addition, development sleeve 41a is rotatably driven in development part on the sense of rotation X as the direction contrary with the sense of rotation Y of photosensitive drums 1a.As a result, be efficiently collected in the developing apparatus in the image forming apparatus of cleaner-less by the subband electric installation that will describe below or the again charged transfer printing residual toner of Charging system or demist toner.
According to this exemplary embodiment, (namely magnetic carrier in two-component developing agent has the particle diameter of the body resistivity of about 1013 Ω cm and about 40 μm, Volume average particle diameter, use laser diffraction type particle size measurement equipment HEROS (by Nippon Denshi Co., Ltd manufactures) measure this Volume average particle diameter by the scope of 0.5 ~ 350 μm being divided into logarithmically 32 parts, and wherein provide the mid diameter of 50% volume to be confirmed as volume average particle size).In addition, nonmagnetic toner is formed, to provide the dusty material of the Volume average particle diameter with about 7 μm by mainly comprising the resin of polyester and the colorant be dispersed in wherein or charge control agent.Nonmagnetic toner is negative polarity by friction magnetic carrier by frictional electrification.
High-voltage power supply 102a applies predetermined visualization bias voltage to development sleeve 41a.According to this exemplary embodiment, developing bias voltage is the oscillating voltage of DC voltage and AC voltage superposition.More specifically, developing bias voltage is the DC voltage of-500V and the oscillating voltage of AC voltage superposition of square wave with 8.0kHz frequency and peak-to-peak voltage Vpp=1.8kV.Therefore, electrostatic latent image discharged-area development is made based on above-mentioned developing bias and the electric field of electrostatic latent image that formed on the surface of photosensitive drums 1a.
In above process, at temperature 23 DEG C and absolute amount of moisture 10g/m 3environment under, the carried charge of the toner that photosensitive drums 1a develops is about-25 μ C/g.
Transfer process will be described below.The developer image that photosensitive drums 1a is formed is transferred to intermediate transfer belt 11 by the primary transfer device 7a in image forming apparatus 100.According to this exemplary embodiment, primary transfer device 7a is the transfer roll 7a being prompted to be pressed into contact with predetermined plus-pressure and photosensitive drums 1a.High-voltage power supply 103a applies the transfer bias of the positive polarity as the contrary polarity of the charged polarity (that is, negative polarity) with toner to transfer roll 7a.According to this exemplary embodiment, the transfer bias of+2kV is applied to transfer roll 7a.Therefore toner is transferred to intermediate transfer belt 11.
Subband electric process will be described below.May exist and not have from the developer image developed at photosensitive drums 1a by the transfer printing residual toner of primary transfer or mist toner.This residual toner or mist toner are sent to upstream subband electric installation 51a and downstream subband electric installation 52a, and then the charged polarity of toner is adjusted to conventional belt electricity condition.According to this exemplary embodiment, upstream subband electric installation 51a and downstream subband electric installation 52a is band brush.But subband electric installation is not limited to the brush component fixed, and can be the parts with any suitable shape, such as scopiform rotary part, resilient roller or sheet shape part.
Upstream subband electric installation 51a is connected with high-voltage power supply 104a, and downstream subband electric installation 52a is connected with high-voltage power supply 105a.High-voltage power supply 104a upstream subband electric installation 51a applies the DC voltage with the polarity contrary with the conventional belt electric polarity (i.e. negative polarity) of toner.According to this exemplary embodiment, the voltage of+300V is applied to upstream subband electric installation 51a.In addition, high-voltage power supply 105a applies the DC voltage with the polarity identical with the conventional belt electric polarity (i.e. negative polarity) of toner to downstream subband electric installation 52a.According to this exemplary embodiment, the voltage of-800V is applied to downstream subband electric installation 52a.Therefore the charged polarity of residual toner is after transfer adjusted to the negative polarity as conventional belt electricity condition by upstream subband electric installation 51a and downstream subband electric installation 52a.
Then wherein the oscillating electric field adjustment of DC voltage and AC voltage superposition has been adjusted to the carried charge of the electropolar residual toner after transfer of conventional belt.Therefore the carried charge distribution of toner becomes narrow areal distribution.
Then, developing apparatus 4a collects its carried charge controlled transfer printing residual toner and mist toner by the demist current potential (Vback) applying+200V.Developing apparatus 4a collects toner while execution developing process.Demist current potential (Vback) is the potential difference (PD) between the dark potential (Vd) (that is, the current potential of non-imaged part) and the DC voltage (Vdc) being applied to development sleeve 41 of photosensitive drums.
The image of four cleaner-less as above forms station and is arranged concurrently, and therefore forms coloured image by four image forming portion Pa, Pb, Pc and Pd.
Clearance maintaining member will be described below.Fig. 4 is the schematic diagram of the clearance maintaining member 49 in the maintenance S-D gap illustrated according to this exemplary embodiment.With reference to Fig. 4, clearance maintaining member 49 has curved surface A and circumferential surface B.Curved surface A contacts with photosensitive drums 1a, and the end axis of development sleeve 41 passes through circumferential surface B and contacts with circumferential surface B.The curvature of curved surface A and circumferential surface B is respectively approximately equal to the photosensitive drums 1a and development sleeve 41 that are in contact with it.According to this exemplary embodiment, clearance maintaining member 49 is formed by polyamide (PA).Clearance maintaining member 49 can also be formed by the resin of such as polyphthalamide (PPA), polyphenylene sulfide (PPS), polyamidoimide (PAI) and polyoxymethylene (POM) and so on.By clearance maintaining member 49 from development sleeve side pressure to photosensitive drums side, so that adjacent photosensitive drums, therefore keep S-D gap.
Because the contact area between the clearance maintaining member that is shaped as illustrated in fig. 4 and photosensitive drums is large, therefore plus-pressure becomes dispersion, and reduces the wearing and tearing of clearance maintaining member.In addition, even if when toner becomes block (agglomerate) or carrier is sandwiched between photosensitive drums and clearance maintaining member, also there is the periodic change in the S-D gap between development sleeve and photosensitive drums hardly.
But if repeatedly perform a large amount of image forming courses, then curved surface A contacts with photosensitive drums 1 and causes the friction with photosensitive drums 1, and the ends contact of the axle of circumferential surface B and development sleeve 41 and cause the friction with the end of the axle of development sleeve 41.Therefore the curved surface A of clearance maintaining member 49 and circumferential surface B becomes and is worn, and S-D gap turn narrow.If S-D gap becomes too narrow, then development sleeve 41 to carry and the developer transmitted by development sleeve 41 becomes and is difficult to by S-D gap, make the delay that developer occurs in the region of S-D air gap periphery.
The mechanism of the delay caused by the change in S-D gap will be described below.The delay of developer is described below with reference to Fig. 5, Fig. 6 A, Fig. 6 B and Fig. 7.Fig. 5 is the schematic diagram in the region illustrated around according to the developing cell in the image forming apparatus of this exemplary embodiment.With reference to Fig. 5, the be fixed magnetic force of the magnet 42 be arranged in development sleeve 41 of the two-component developing agent comprising nonmagnetic toner T and magnetic color tuner C pulls to development sleeve 41.The side that the arrow X of non magnetic development sleeve 41 shown in Fig. 5 points out rotates up, and by performing sandblasting (blast) process, the surfaceness Rz of this non magnetic development sleeve 41 is treated to 10 μm.Therefore while fringe (ear) is stood, by arrow X indicated direction being carried and transmitting two-component developing agent.
In addition, photosensitive drums 1 (that is, on the direction contrary with the rotation of development sleeve 41) on the position of relatively placing photosensitive drums 1 with development sleeve 41 is in as shown in Figure 5 arrow Y indicated direction rotates.If S-D gap turn narrow, the developer that its fringe is stood contacts with photosensitive drums 1, makes the tangential conveying capacity caused by the rotation of development sleeve 41 become interruption.As a result, developer becomes and is difficult to by S-D gap, and must be less than by the quantitative change of the developer in S-D gap and carry and be sent to the amount of the developer in S-D gap.Therefore there is the delay of developer.
Make the delay of developer occur in position away from development sleeve 41 if the amount of the developer retained increases, then the magnetic force (that is, for keeping developer towards the power of development sleeve 41) of magnet 42 dies down.As a result, developer sleeve 41 can not keep developer, and therefore transmits developer along the sense of rotation Y of photosensitive drums 1.
Fig. 6 A and Fig. 6 B illustrates the electric field (Fig. 6 A) formed in blank parts and the electric field (Fig. 6 B) formed in pure color (solid) part.According to the present invention, image forming apparatus uses discharged-area development method, and wherein exposure device formed electrostatic latent image part on charge image developing toner.In addition, developer stirs nonmagnetic toner and the magnetic carrier of developing apparatus 4 inside, to apply electric charge by frictional electrification.Therefore nonmagnetic toner by charged be negative polarity (-), and magnetic carrier by charged be positive polarity (+).
With reference to Fig. 6 A, the photosensitive drums current potential (Vd) in blank parts and development sleeve current potential (Vdc) are in demist current potential (Vback) state.According to this exemplary embodiment, photosensitive drums current potential Vd is set to-700V, and development sleeve current potential Vdc is set to-500V.Then the toner of negative polarity remains on development sleeve current potential (Vdc).But, make the carrier of positive polarity mobile towards the photosensitive drums current potential (Vd) with more negative current potential.Then different from the tangential force E caused by the rotation by development sleeve 41 power F becomes and is applied to photosensitive drums 1 from development sleeve 41, and the transfer rate of developer is reduced.Therefore the delay that developer may occur in S-D gap is become.
In addition, with reference to Fig. 6 B, exposure device makes the photosensitive drums current potential in solid-color image part become sub-image current potential (VL).In this case, the potential difference (PD) between development sleeve current potential (Vdc) and sub-image current potential (VL) becomes contrast current potential (Vcont).
According to this exemplary embodiment, even if when by performing image color control break sub-image current potential VL, the sub-image current potential VL in solid-color image is also set to about-140V to-300V.Therefore power becomes the toner being applied to negative polarity, makes toner mobile towards the sub-image current potential (VL) that its current potential is more positive.The carrier of positive polarity remains on development sleeve current potential (Vdc).
But when solid-color image, the amount of the toner that photosensitive drums is developed is large, makes carrier also be developed in photosensitive drums together with the toner adhering electrostatically to carrier surface.Therefore there is the adhesion of the carrier in solid-color image.Then different from the tangential force E caused by the rotation by development sleeve 41 power F becomes and is applied to photosensitive drums 1 from development sleeve 41.As a result, the transfer rate of developer reduces, and becomes the delay that developer may occur in S-D gap.
Fig. 7 illustrates the curve map according to the demist current potential (Vback) of this exemplary embodiment, the relation between S-D gap and the delay of developer.Graphical representation shown in Fig. 7 wherein according to occur in the image forming apparatus of this exemplary embodiment be detained condition.Every 1cm 2the developer level (M/S) that is coated on the developing location of development sleeve of area be 35mg/cm 2.With reference to Fig. 7, if clearance maintaining member 49 be worn and S-D gap turn narrow to 240 μm, and Vback is set to be greater than or equal to 200V, then the delay of developer occurs in blank parts.If produce wearing and tearing further, and S-D gap turn narrow is to 210 μm, then the delay of developer occurs in blank parts when Vback is set to be greater than or equal to 80V.The delay of developer is there is due to following reason.The power being applied to photosensitive drums 1 in the directionf from development sleeve 41 increases along with Vback and increases, and the developer transfer rate of development sleeve 41 is reduced.In other words, change narrow along with S-D gap and along with Vback increase, become the delay that developer may occur.Similarly, along with contrast current potential Vcont increases, the delay that developer more may occur is become.
The control performed according to this exemplary embodiment is described below with reference to Fig. 8, Fig. 9, Figure 10, Figure 11 and Figure 12.
The control (that is, first controlling) of Vback will be described below.Fig. 8 is the block diagram that control module and the detecting unit controlled according to the execution of this exemplary embodiment is shown.With reference to Fig. 8, control module comprises CPU 61.Environmental sensor 80 and the photosensitive drums rotation detecting circuit 71 of CPU 61 and the environment that will be used as around the RAM 62 of working storage, the ROM 63 storing program and the various data that will be performed by CPU, detected image forming device are connected.In addition, CPU 61 with development sleeve rotation detecting circuit 72, the exposure device 3 that applying to be with the live high voltage power supply 101 of electrical bias to the Charging system 2 for making photosensitive drums 1 charged, applying the development high-voltage power supply 102 of developing bias to development sleeve 41 and forming electrostatic latent image is connected.
Fig. 9 is the process flow diagram illustrated for performing the process of high voltage control according to the driving of development sleeve.
In step sl, image forming apparatus starts operation.In step s 2, CPU 61 is from backing up the development count value D (that is, the integrated value of the drive volume of development sleeve) reached before RAM 62 reads in present image forming process.In step s3, the humidity and temperature around environmental sensor 80 detected image forming device.
In step s 4 which, development sleeve rotation detecting circuit 72 calculates development count value D based on total driving time of the development sleeve detected since the initial installation or replacement of developing apparatus.By the driving time TS of development sleeve is calculated except for the driving time TS0 forming the development sleeve of image on a sheet material count value D that develops.Therefore driving time TS is converted to the number of the corresponding image formed.In other words, the count value D that develops is corresponding with the total quantity of the rotation of development sleeve.According to this exemplary embodiment, developing apparatus or the handle box comprising developing apparatus are integrally replaced.Therefore, it is possible to detected the deterioration of developer by the initial installation from developing apparatus of acquisition development sleeve or the rotation quantity replacing.
When performing driving development sleeve in the various controls in the process except image forming course (such as, image color control, color misalignment Corrective control and toner concentration control), development sleeve driving time TS is upwards counted.In addition, when driving development sleeve when being unlocked at image forming apparatus or recovering from park mode the many rotations of preparation, development sleeve driving time TS is upwards counted.
In step s 5, CPU 61 determines the setting of demist current potential (Vback) as shown in Figure 10 based on calculated development count value D and environmental data.In step s 6, CPU61 determines based on the environment table comprising band electrical bias and developing bias and applies the voltage of live high voltage power supply 101 and development high-voltage power supply 102.In the step s 7, image forming course is performed.
Figure 10 illustrates for the Vback table according to development count value D control Vback.With reference to Figure 10, solid line 1 represents the use table of the demist current potential in low-humidity environment (that is, absolute moisture is 1.0g).Dotted line 2 represents the use table of the demist current potential in high humidity environment (that is, absolute moisture is 22.0g).With reference to solid line 1 and dotted line 2, perform and control to increase along with development count value D and to increase demist current potential Vback.In addition, in high humidity environment, for the reason that will describe below, compared with low-humidity environment, along with development sleeve is used further, demist current potential Vback increases further.
When driving development sleeve 41, the two-component developing agent in developing apparatus 4 is stirred, and the adjustment member 43 shown in Fig. 2 regulates and on development sleeve 41, applies the thin layer of developer.In this case, the friction between developer occurs, or developer is crushed on developer pond (pool) place in the upstream portion of the sense of rotation relative to development sleeve 41 of adjustment member 43.As a result, be attached to the silica on the surface of the toner in developer or titanium and become and be embedded into or depart from, or toner becomes the surface being fused to magnetic carrier, makes to become to reduce charged toner amount.
The impact of the more impossible electric field be subject in developing cell of the toner of low carried charge.Even if therefore also there is such as wherein toner when applying demist current potential Vback to be attached to the picture failure of the atomization of the blank parts of photosensitive drums and so on.In order to address this is that, increase demist current potential Vback, making not to be atomized when toner has low carried charge.In addition, in high humidity environment, owing to being attached to the moisture of carrier, toner or external additive, surface resistivity and body resistivity are reduced.Therefore become and be difficult to apply electric charge by friction, make charged toner quantitative change low.In this case, demist current potential Vback increases further.
To control according to first of this exemplary embodiment above-mentioned, the driving time TS0 of the driving time TS based on development sleeve and the development sleeve for the formation of an image calculates development count value D (that is, the integrated value of the drive volume of development sleeve).But, the invention is not restricted to above.Such as, driving time TS directly can be set as the count value D that develops.In this case, accuracy of detection is reduced a little.In addition, the integrated value of the quantity of image sheet material formed can be used directly as development count value D.In addition, the driving time of stirring screw or the driving time of photosensitive drums of the developer stirred in developing apparatus can be used, instead of the driving time of development sleeve.
The Vback described in response to the wearing and tearing of clearance maintaining member 49 below with reference to Figure 11 and Figure 12 controls (that is, second controlling).
Figure 11 is the process flow diagram illustrated for performing the process of high voltage control according to the wear extent of clearance maintaining member.
According to this exemplary embodiment, by detect about from the initial installation of developing apparatus or since replacing the information of the drive volume of development sleeve obtain the wear extent Z of clearance maintaining member.According to the present invention, the handle box or the developing apparatus that comprise developing apparatus are integrally replaced together with clearance maintaining member.Therefore from initial install or replace since the quantity of rotation of development sleeve corresponding with the wear extent of clearance maintaining member.
In step s 11, image forming apparatus starts operation.In step s 12, CPU 61 is from the wear extent Z backing up the clearance maintaining member produced before RAM 62 reads in present image forming process.In step s 13, the humidity and temperature around environmental sensor 80 detected image forming device.In step S14, use the photosensitive drums 1 that detected by photosensitive drums rotation detecting circuit 71 from the replacement of developing apparatus or initial install since driving time TD to calculate wear extent Z.Also use the driving time TS of the development sleeve 41 detected by development sleeve detecting unit 72 to calculate wear extent Z.Therefore, wear extent Z is calculated as the summation of the wear extent caused by the driving of photosensitive drums and the wear extent caused by the driving of development sleeve.
To be worn 10 μm at the curved surface A that photosensitive drums 1 is driven to formation 30000 image temporal gap holding members 49 by supposition and to calculate the wear extent caused by the driving of photosensitive drums.Be multiplied by 10/30000 (μm/) by the recruitment of the driving time TD by the photosensitive drums 1 in body operation calculate wear extent divided by the driving time TD0 of the photosensitive drums 1 for the formation of an image.In addition, to be worn 20 μm at the circumferential surface B that photosensitive drums 1 is driven to formation 30000 image temporal gap holding members 49 by supposition and to calculate the wear extent caused by the driving of development sleeve.Be multiplied by 20/30000 (μm/) by the recruitment of the driving time TS by the development sleeve 41 in body operation calculate wear extent divided by the driving time TS0 of the development sleeve 41 for the formation of an image.Therefore the wear extent of prediction gap holding member.
The mechanism for primary transfer device 7a, 7b, 7c and 7d and photosensitive drums 1a, 1b, 1c and 1d being separated is not comprised according to the image forming apparatus of this exemplary embodiment.As a result, when image forming apparatus fill order color image forming process, drive photosensitive drums 1a, 1b, 1c and 1d.In addition, when image forming apparatus fill order color image forming process, the development sleeve 41d comprising black reagent among development sleeve 41a, 41b, 41c and 41d is driven.But, do not drive development sleeve 41a, 41b and 41c of comprising yellow developer, magenta developer and blue developer respectively.If then image forming apparatus performs full-colour image forming process, then form station Pa, Pb, Pc and the curved surface A contacted with photosensitive drums 1 of the clearance maintaining member as shown in Figure 4 49 in Pd at image and all wear and tear in the circumferential surface B that contacts with development sleeve 41.
When image forming apparatus fill order color image forming process, all wear and tear in the curved surface A contacted with photosensitive drums 1 of the clearance maintaining member 49 in black image formation station Pd and the circumferential surface B contacted with development sleeve 41.On the other hand, wearing and tearing are being become with the curved surface A contacted with photosensitive drums 1 that yellow, that magenta is corresponding with cyan image forms only clearance maintaining member 49 in stand Pa, Pb and Pc.Therefore wear extent Z is different according to image formation station and imaging pattern.
In step S15, CPU 61 determines whether calculated wear extent Z is greater than 30 μm.If CPU 61 determines that wear extent Z is greater than 30 μm (being "Yes" in step S15), then process proceeds to step S16.In step s 16, CPU 61 calculates Vback side-play amount W according to wear extent.According to this exemplary embodiment, the setting value in S-D gap is 300 ± 20 μm that comprise tolerance, and brings into use the processing unit of the lower limit of tolerance from the setting value of 280 μm.If as shown in Figure 7 clearance maintaining member is worn 30 μm and S-D gap becomes 250 μm, then there is the delay of developer when demist current potential Vback is set to be greater than or equal to 250V.In this case, perform and control to reduce Vback, thus prevent the delay of developer.
As mentioned above, based on the integrated value of the driving time of development sleeve, the value that there is Vback is wherein reduced to the period of the delay of the developer caused by change suppressing the S-D gap caused by the wearing and tearing due to clearance maintaining member.For following reason, calculate Vback side-play amount W by increasing the side-play amount of-6V for the wearing and tearing of every 1 μm when wear extent is more than 30 μm.With reference to Fig. 7, when S-D gap turn narrow 10 μm, become and Vback must be reduced 45V.If decreased by Vback more than 45V, then the delay of developer does not occur.
In step S17, CPU 61 will be added to the setting of the demist current potential Vback shown in Fig. 9 based on development count value D and environmental data according to the Vback side-play amount W of wear extent.In step S19, then CPU 61 determines based on the environment table comprising band electrical bias and developing bias and applies the high pressure setting of live high voltage power supply 101 and development high-voltage power supply 102.In step S20, perform image forming course.
If CPU 61 determines that calculated wear extent Z is less than or equal to 30 μm (being "No" in step S15), then process proceeds to step S18.In step S18, CPU 61 sets Vback based on development count value D as shown in Figure 9.In step S19, then CPU 61 determines and applies high pressure setting.In step S20, perform image forming course.
According to this exemplary embodiment, the Vback performed with the deterioration in response to developer controls, and (that is, first controlling) is compared, and (namely the Vback performed in the wearing and tearing in response to clearance maintaining member controls, second controls) in, the knots modification of Vback is larger.As a result, if wear extent is more than 30 μm, then performs and control to reduce Vback along with the rotation quantity increase of development sleeve.
In addition, the Vback performed in response to the wearing and tearing of clearance maintaining member at the place of slower stage used controls (that is, second controlling).On the other hand, compared with controlling with second, the stage place's execution first more early controls.Therefore, exist wherein Vback increase in case prevent the period of developer degradation and then wherein Vback reduce to correspond to the period of the delay of the developer caused by the wearing and tearing of clearance maintaining member.This switching between the period is performed along with the use of image forming apparatus.
The control of the contrast current potential Vcont performed in response to the wearing and tearing of clearance maintaining member will be described below.Figure 12 is the process flow diagram of the process illustrated for controlling contrast current potential Vcont according to the wear extent of clearance maintaining member.According to this exemplary embodiment, control contrast current potential by the light quantity controlling laser instrument (that is, exposing unit).
In step 22, image forming apparatus starts operation.In step S23, CPU 61 reads in the wear extent Z of the clearance maintaining member before present image forming process from backup RAM 62.In step s 24 which, the humidity and temperature of environmental sensor 80 detected image forming device peripheral region.In step s 25, CPU 61 uses the driving time TD of the photosensitive drums 1 detected by photosensitive drums the rotation detecting circuit 71 and driving time TS of development sleeve 41 that detected by development sleeve rotation detecting circuit 72 to calculate wear extent Z.
In step S26, CPU 61 determines whether calculated wear extent Z is greater than 30 μm.If CPU 61 determines that calculated wear extent Z is greater than 30 μm (being "Yes" in step S26), then process proceeds to step S27.In step s 27, CPU 61 is according to the upper limit of the laser power of wear extent calculation exposure device 3.According to this exemplary embodiment, when photosensitive drums by uniform charged to Vd=-700V time, if the photosensitive drums of sub-image in image forming apparatus is formed make laser power become 0.32 μ J/cm 2the surperficial light quantity of drum, then sub-image current potential VL becomes-140V.
In addition, if sub-image is formed to make laser power become 0.26 μ J/cm 2the surperficial light quantity of drum, then sub-image current potential VL becomes-172V.In addition, if sub-image is formed to make laser power become 0.20 μ J/cm 2the surperficial light quantity of drum, then sub-image current potential VL becomes-224V.When Vback is set to 200V, developing bias current potential Vdc=-500V.Due to contrast current potential Vcont=Vdc-VL, therefore become lower at a laser power hour contrast current potential, and the delay of more impossible generation developer.According to this exemplary embodiment, perform the calculating of the upper limit of laser power, make the upper limit become the laser power of light quantity, wherein when wear extent is more than 30 μm for the wearing and tearing of 1 μm, sub-image current potential VL step-down-5V.
In step S28, if the laser power controlling to determine by performing image color is greater than the upper limit of laser power, then laser power settings is the upper limit of laser power by CPU 61.On the other hand, if the laser power controlling to determine by performing image color is less than the upper limit of laser power, then CPU 61 uses the laser power controlling to determine by performing image color.In step S29, CPU 61 sets the laser power of exposure device 3.In step s 30, image forming course is performed.
If CPU 61 determines that calculated wear extent Z is less than or equal to 30 μm (being "No" in step S26), then process proceeds to step S29.In step S29, the laser power that CPU 61 sets exposure device 3 is the laser power controlling to determine by performing image color.In step s 30, image forming course is performed.
By performing above-mentioned control, predict the wear extent of the clearance maintaining member between photosensitive drums and development sleeve according to the driving time of photosensitive drums and the driving time of development sleeve.Then demist current potential and contrast current potential is controlled according to wear extent.As a result, even if when narrowing due to the wearing and tearing of clearance maintaining member caused by performing great amount of images forming process in S-D gap, also there is not the delay of developer.
According to this exemplary embodiment, distance (that is, S-D gap) nearest between photosensitive drums and development sleeve is kept by clearance maintaining member.Clearance maintaining member is attached to axially two ends of development sleeve, so that adjacent photosensitive drums.Therefore the image in image forming apparatus forms station and keeps S-D gap.Then the wear extent of prediction gap holding member is carried out according to the driving time of photosensitive drums and the driving time of development sleeve.Therefore demist current potential is reduced according to wear extent.In addition, performing control makes contrast current potential greatly constant.As a result, developer is prevented to be detained at development sleeve and photosensitive drums areas adjacent facing with each other.In addition, the inefficacy that the developer owing to comprising magnetic carrier causes from developing apparatus spilling can be prevented.
According to this exemplary embodiment, the image forming apparatus of cleaner-less comprises upstream subband electric installation 51 and downstream subband electric installation 52.But this is not restriction, and similar effect can be obtained by performing above-mentioned control in the image forming apparatus of the photosensitive drums cleaning device instead of subband electric installation that comprise clean transfer printing residual toner.Describe this equipment in fig. 13.
In addition, according to this exemplary embodiment, clearance maintaining member is formed as illustrated in fig. 4.But, also can use cylindrical gap holding member as shown in figure 14.When there is difference in development sleeve and photosensitive drums part respect to one another between development sleeve and photosensitive drums, always produce the friction with photosensitive drums and/or development sleeve.Therefore, being worn with the surface in contact A of photosensitive drums 1 and becoming with the surface in contact B of development sleeve 41 of clearance maintaining member 49, and S-D gap turn narrow.In the processing unit comprising this clearance maintaining member, also can prevent the delay of developer near development sleeve and photosensitive drums part respect to one another by performing similar control.
In addition, according to this exemplary embodiment, image forming apparatus adopts the sense of rotation of development sleeve and photosensitive drums in the part of wherein placing relative to one another at development sleeve and photosensitive drums to be rightabout developing method.But this is not restriction.Be can obtain similar effect in the image forming apparatus of the developing method of equidirectional adopting the sense of rotation of development sleeve and photosensitive drums in the part of wherein placing relative to one another at development sleeve and photosensitive drums.
Below with reference to Figure 15, the second exemplary embodiment is described.According to the first exemplary embodiment, clearance maintaining member 49 is formed as material by polyamide.According to this exemplary embodiment, clearance maintaining member is formed by resin component and bearing (bearing).Other configuration is similar with the first exemplary embodiment, thus identical Reference numeral is assigned to identical assembly, and by the descriptions thereof are omitted.
Figure 15 illustrates the clearance maintaining member 49 according to the second exemplary embodiment.With reference to Figure 15, comprise resin component 491 and bearing 492 according to the clearance maintaining member 49 of this exemplary embodiment.Resin component 491 and the first exemplary embodiment are formed as material by polyamide similarly.The curved surface A of resin component 491 adjoins photosensitive drums 1, and the end axis of development sleeve 41 is by bearing 492.Therefore clearance maintaining member 49 is adjacent photosensitive drums side from development sleeve side pressure, and keeps S-D gap.
In this clearance maintaining member, when driving photosensitive drums 1, curved surface A becomes and is worn, and makes S-D gap turn narrow.But the adjacent part on development sleeve 41 due to clearance maintaining member 49 is bearing 492, even if therefore also do not wear and tear when driving development sleeve 41, and S-D gap does not narrow.According to this exemplary embodiment, the therefore wear extent Z of prediction gap holding member as follows.Be multiplied by 10/30000 (μm/) by the recruitment of the driving time TD by the photosensitive drums in body operation predict wear extent Z divided by the driving time TD0 of the photosensitive drums for the formation of an image.
Therefore, the wear extent Z of prediction gap holding member 49 as described above, and control demist current potential and contrast current potential similarly with the first exemplary embodiment.As a result, even if there is not the delay of developer when clearance maintaining member is worn owing to performing a large amount of image forming courses yet, and S-D gap turn narrow.In addition, for the quantity of sheet material being formed with image thereon, the wear extent of clearance maintaining member is less, makes to obtain the longer life-span.
Below with reference to Figure 16, the 3rd exemplary embodiment is described.According to the first exemplary embodiment, the wear extent of prediction gap holding member, and control demist current potential Vback and contrast current potential Vcont when wear extent becomes and is more than or equal to scheduled volume.In contrast, according to this exemplary embodiment, wear extent become be more than or equal to predetermined value time, notify that user replaces image formation unit.As a result, replace together with image formation unit with urgency user and perform the control similar with the first exemplary embodiment.Other configuration is similar with the first exemplary embodiment, thus identical Reference numeral is assigned to identical assembly, and by the descriptions thereof are omitted.
Figure 16 illustrates the process flow diagram for performing the process of high voltage control according to the wear extent of clearance maintaining member according to this exemplary embodiment.
In step S41, image forming apparatus starts operation.In step S42, CPU 61 reads in the wear extent Z of the clearance maintaining member before present image forming process from backup RAM 62.In step S43, the humidity and temperature of environmental sensor 80 detected image forming device peripheral region.In step S44, CPU 61 uses the driving time TS of the driving time TD of photosensitive drums 1 and development sleeve 41 to calculate wear extent Z.In step S45, CPU61 determines whether calculated wear extent Z is greater than 30 μm.If CPU 61 determines that calculated wear extent Z is greater than 30 μm (being "Yes" in step S45), then process proceeds to step S46.In step S46, the replacement timing of CPU 61 Graphics Processing box P on the guidance panel of image forming apparatus.
In step S47, CPU 61 calculates Vback side-play amount W according to wear extent.In step S48, CPU 61 will be added to the setting of demist current potential Vback as shown in Figure 10 based on development count value D and environmental data according to the Vback side-play amount W of wear extent.In step s 50, then CPU 61 determines to set with applying high voltage based on the environment table comprising band electrical bias and developing bias.In step s 51, image forming course is performed.
If CPU 61 determines that calculated wear extent Z is less than or equal to 30 μm (being "No" in step S45), then process proceeds to step S49.In step S49, CPU 61 sets Vback based on development count value D as shown in Figure 9.In step s 50, CPU 61 determines to set with applying high voltage.In step s 51, image forming course is performed.
By performing above-mentioned control, the wear extent of prediction gap holding member, and when wear extent become be more than or equal to predetermined value time, guidance panel performs and urges user to replace the display of handle box.In addition, even if be worn owing to performing a large amount of image forming courses at clearance maintaining member, and when S-D gap narrows, be there is not the delay of developer by the control performing demist current potential and contrast current potential yet.In addition, by urging user to replace handle box and making user replace the delay that handle box prevents developer safely before generation further wearing and tearing.
In addition, when calculating wear extent when the clearance maintaining member used according to the second exemplary embodiment and based on the driving time of photosensitive drums, similar effect can be realized by performing similar control.
In addition, according to this exemplary embodiment, the handle box P comprising photosensitive drums and developing apparatus is detachably attached to image forming apparatus 100.But, can by using the developing apparatus 4 comprising clearance maintaining member that is removably attached to image forming apparatus 100 and urging user to replace developing apparatus 4 obtaining similar effect.
Below with reference to Figure 17, the 4th exemplary embodiment is described.According to the first exemplary embodiment, the wear extent of prediction gap holding member, and control demist current potential and contrast current potential when wear extent becomes and is more than or equal to scheduled volume.In contrast, according to this exemplary embodiment, wear extent become be more than or equal to predetermined value time, stop the image forming course being performed by image forming apparatus.Then notify that user replaces handle box.Other configuration is similar with the first exemplary embodiment, thus identical Reference numeral is assigned to identical assembly, and by the descriptions thereof are omitted.
Figure 17 illustrates the process flow diagram for replacing the process of handle box Pa, Pb, Pc and Pd based on the wear extent indicating user of clearance maintaining member according to this exemplary embodiment.
In step S61, image forming apparatus starts operation.In step S62, CPU 61 reads in the wear extent Z of the clearance maintaining member before present image forming process from backup RAM 62.In step S63, the humidity and temperature of environmental sensor 80 detected image forming device peripheral region.In step S64, CPU 61 uses the driving time TS of the driving time TD of photosensitive drums 1 and development sleeve 41 to calculate wear extent Z.In step S65, CPU61 determines whether calculated wear extent Z is greater than 30 μm.If CPU 61 determines that calculated wear extent Z is greater than 30 μm (being "Yes" in step S65), then process proceeds to step S66.
In step S66, the guidance panel of CPU 61 in image forming apparatus shows the instruction of replacing handle box P.In step S67, CPU 61 stops at the image forming course performed in image forming apparatus 100, and stops receiving the instruction of image formation processing.On the other hand, if CPU 61 determines that calculated wear extent Z is less than or equal to 30 μm (being "No" in step S65), then process proceeds to step S69.In step S69, perform image forming course.
By performing above-mentioned control, the wear extent of prediction gap holding member.Wear extent become be more than or equal to predetermined value time, stop image forming course, and show on guidance panel replacement handle box instruction.As a result, user replaces handle box, makes the delay strictly preventing developer.
In addition, similar effect can be realized by performing similar control when using clearance maintaining member according to the second exemplary embodiment and calculating wear extent based on the driving time of photosensitive drums.
In addition, according to this exemplary embodiment, the handle box P comprising photosensitive drums and developing apparatus removably attaches to image forming apparatus 100.But, the developing apparatus 4 comprising clearance maintaining member that removably attaches to image forming apparatus 100 can be used and urge user to replace developing apparatus 4 to obtain similar effect.
According to the present invention, image forming apparatus can reduce the inefficacy caused by the delay of the developer occurred in region that wherein development sleeve and photosensitive drums place relative to one another.This delay of developer is there is owing to keeping the wearing and tearing of the clearance maintaining member in the gap between developer bearing part and image bearing member by contiguous image load bearing component.
Although reference example embodiment describes the present invention, should be appreciated that and the invention is not restricted to disclosed exemplary embodiment.The scope of following claim will be given the widest explanation thus comprise all amendments, equivalent structure and function.

Claims (4)

1. an image forming apparatus, comprising:
Image bearing member;
Developing apparatus, described developing apparatus is included in the developer bearing part relatively arranged with described image bearing member in developing regional, and be configured to the latent electrostatic image developing making to be formed on described image bearing member, described developer bearing part carries and transmits the developer comprising nonmagnetic toner and magnetic carrier;
Clearance maintaining member, described clearance maintaining member is integrally replaced together with described developing apparatus, and be configured to remain on distance between described image bearing member and described developer bearing part by adjacent described image bearing member and described developer bearing part, described clearance maintaining member comprises the bearing adjacent with described developer bearing part; And
Control device, the increase that described control device is configured to the integrated value performing the drive volume according to described image bearing member when the integrated value of the drive volume of described image bearing member is greater than predetermined value reduces the pattern of the potential difference (PD) between the current potential and the developing bias being applied to described developer bearing part of the non-image portion of described image bearing member
The integrated value of the drive volume of wherein said image bearing member has been the accumulation drive volume from the initial installation of described developing apparatus or the image bearing member reached before present image forming process since replacing.
2. an image forming apparatus, comprising:
Image bearing member;
Developing apparatus, described developing apparatus is included in the developer bearing part relatively arranged with described image bearing member in developing regional, and be configured to the latent electrostatic image developing making to be formed on described image bearing member, described developer bearing part carries and transmits the developer comprising nonmagnetic toner and magnetic carrier;
Clearance maintaining member, described clearance maintaining member is integrally replaced together with described developing apparatus, and is configured to remain on distance between described image bearing member and described developer bearing part by adjacent described image bearing member and described developer bearing part; And
Control device, described control device is configured to when the value that will calculate according to the integrated value of the drive volume of the integrated value of the drive volume of described developer bearing part and described image bearing member is greater than predetermined value, the increase of the value calculated described in described control device execution basis reduces the pattern of the potential difference (PD) between the current potential and the developing bias being applied to described developer bearing part of the non-image portion of described image bearing member
The integrated value of the drive volume of wherein said developer bearing part has been from the initial installation of described developing apparatus or the development count value reached before present image forming process since replacing,
The integrated value of the drive volume of wherein said image bearing member has been the accumulation drive volume from the initial installation of described developing apparatus or the image bearing member reached before present image forming process since replacing.
3. image forming apparatus according to claim 1 and 2, wherein said clearance maintaining member slides relative to the turning axle of described developer bearing part.
4. an image forming apparatus, comprising:
Image bearing member;
Developing apparatus, described developing apparatus is included in the developer bearing part relatively arranged with described image bearing member in developing regional, and be configured to the latent electrostatic image developing making to be formed on described image bearing member, described developer bearing part carries and transmits the developer comprising nonmagnetic toner and magnetic carrier;
Clearance maintaining member, described clearance maintaining member is integrally replaced together with described developing apparatus, and is configured to remain on distance between described image bearing member and described developer bearing part by adjacent described image bearing member and described developer bearing part; And
Notifying device, the situation that described notifying device is configured to be greater than predetermined value in the value that will calculate according to the integrated value of the drive volume of the integrated value of the drive volume of described developer bearing part and described image bearing member sends a notice and replaces described developing apparatus,
The integrated value of the drive volume of wherein said developer bearing part has been from the initial installation of described developing apparatus or the development count value reached before present image forming process since replacing,
The integrated value of the drive volume of wherein said image bearing member has been the accumulation drive volume from the initial installation of described developing apparatus or the image bearing member reached before present image forming process since replacing.
CN201110344603.XA 2010-11-04 2011-11-04 Image forming apparatus Expired - Fee Related CN102467028B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010247861A JP5284333B2 (en) 2010-11-04 2010-11-04 Image forming apparatus
JP2010-247861 2010-11-04

Publications (2)

Publication Number Publication Date
CN102467028A CN102467028A (en) 2012-05-23
CN102467028B true CN102467028B (en) 2014-12-17

Family

ID=46019728

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201110344603.XA Expired - Fee Related CN102467028B (en) 2010-11-04 2011-11-04 Image forming apparatus

Country Status (3)

Country Link
US (1) US9547251B2 (en)
JP (1) JP5284333B2 (en)
CN (1) CN102467028B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6091180B2 (en) * 2012-11-21 2017-03-08 キヤノン株式会社 Image forming apparatus
JP6241602B2 (en) * 2013-10-24 2017-12-06 株式会社リコー Process unit and image forming apparatus
JP2022076197A (en) * 2020-11-09 2022-05-19 日本電産サンキョー株式会社 Control device for industrial robot

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002296903A (en) * 2001-03-29 2002-10-09 Canon Inc Gap retaining member, process cartridge and image forming device
JP2003076075A (en) * 2001-08-31 2003-03-14 Konica Corp Image forming device
JP2005004110A (en) * 2003-06-13 2005-01-06 Canon Inc Developing device and image forming apparatus

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4021242C2 (en) * 1989-07-04 1996-10-17 Ricoh Kk Electrophotographic printing or copying machine with interchangeable process unit
JPH0572880A (en) * 1991-09-18 1993-03-26 Hitachi Ltd Electrostatic charge image developing device
JPH07175282A (en) 1992-12-21 1995-07-14 Canon Inc Image forming device
JPH07175321A (en) 1993-12-17 1995-07-14 Canon Inc Developing device
JPH10207224A (en) 1997-01-17 1998-08-07 Canon Inc Developing device
JP3476399B2 (en) 1999-10-12 2003-12-10 富士写真フイルム株式会社 Cartridge life detecting method, apparatus and system, cartridge and storage medium
JP3679665B2 (en) 1999-11-19 2005-08-03 キヤノン株式会社 Gap assurance member, developing device, charging device, and process cartridge
JP2002082578A (en) * 2000-09-08 2002-03-22 Konica Corp Image forming method and image forming device
US6785482B2 (en) * 2002-02-22 2004-08-31 Canon Kabushiki Kaisha Image forming apparatus having a transfer current detection device and control for developing bias in non-image area
JP3885030B2 (en) * 2002-02-22 2007-02-21 キヤノン株式会社 Image forming apparatus
JP2004163478A (en) 2002-11-11 2004-06-10 Canon Inc Image forming apparatus
US7509062B2 (en) * 2004-08-16 2009-03-24 Ricoh Company, Ltd. Method and apparatus for image forming capable of effectively recycling image forming unit
JP2007065095A (en) * 2005-08-29 2007-03-15 Ricoh Co Ltd Image forming apparatus
JP4724543B2 (en) * 2005-11-30 2011-07-13 株式会社リコー Component life management apparatus and image forming system
US8045874B2 (en) * 2008-02-07 2011-10-25 Ricoh Company Limited Image forming apparatus and image density control method
JP2009258166A (en) * 2008-04-11 2009-11-05 Sharp Corp Development device
JP4981842B2 (en) * 2009-04-20 2012-07-25 株式会社沖データ Image forming apparatus
JP2011013663A (en) * 2009-06-01 2011-01-20 Canon Inc Image forming apparatus
JP4888547B2 (en) * 2009-12-16 2012-02-29 コニカミノルタビジネステクノロジーズ株式会社 Image forming unit, developing unit, photoconductor unit, and image forming apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002296903A (en) * 2001-03-29 2002-10-09 Canon Inc Gap retaining member, process cartridge and image forming device
JP2003076075A (en) * 2001-08-31 2003-03-14 Konica Corp Image forming device
JP2005004110A (en) * 2003-06-13 2005-01-06 Canon Inc Developing device and image forming apparatus

Also Published As

Publication number Publication date
US20120114348A1 (en) 2012-05-10
JP5284333B2 (en) 2013-09-11
JP2012098629A (en) 2012-05-24
CN102467028A (en) 2012-05-23
US9547251B2 (en) 2017-01-17

Similar Documents

Publication Publication Date Title
US9645528B2 (en) Image forming apparatus having toner collecting mode after stoppage
US7593669B2 (en) Image forming apparatus
US10509355B2 (en) Image forming apparatus
JP2001215799A (en) Image forming device and process cartridge
CN102467028B (en) Image forming apparatus
JPH10307454A (en) Electrifying method and device, image forming device and process cartridge
US9910397B2 (en) Image forming apparatus with speed difference control
JP2008180902A (en) Image forming device
US8208822B2 (en) Image forming apparatus
JP2002333762A (en) Electrifying device and image forming device
JP4772589B2 (en) Image forming apparatus and transfer device used therefor
KR100553907B1 (en) Photosensitive drum having spacer and electrophotographic image forming apparatus usisng the same
JP2005062858A (en) Fog development method and fog development device for image forming apparatus
JP2000081772A (en) Image forming device
JP2006010957A (en) Image recording device
JP2002268332A (en) Charger
CN101581898B (en) Image forming apparatus
JP5535372B2 (en) Image forming apparatus
JPH10149074A (en) Image forming device
US9291957B2 (en) Image forming apparatus with reciprocating mechanism for cleaning blade
JPH10307459A (en) Method and device for electrification, image forming device and process cartridge
JP2000338752A (en) Image forming device
JP2004102140A (en) Apparatus and method for image formation
JP5020772B2 (en) Developing device, image forming apparatus, and process cartridge
JP2006010955A (en) Image recording device

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20141217

Termination date: 20201104

CF01 Termination of patent right due to non-payment of annual fee